Time was, I used to read a lot of systematic theology; I don’t do that much anymore. Rather, I’m much more likely to read commentaries. This is not to disparage the work of systematic theology—I still have a lot of it on my shelves, and I make use of it; but I think the church, at least since Aquinas, has tended to make much too much of theological systems, to the point where we identify with and believe in them rather than in what—or rather, Who—they’re supposed to point us to. Just consider the labels Protestants use: Lutheran, Calvinist, Wesleyan, Baptist, Reformed, Methodist, Presbyterian, Episcopalian. (Those churches which call themselves Catholic and Orthodox are different because they defined themselves against each other—the purpose of their names is to identify them as the true church and the other as not.) I think systematic theology has a useful and important purpose in helping us to interpret Scripture holistically, in the big-picture view, with integrity; but we must always remember that it is merely a guide to understanding, not the substance of our beliefs.
It’s easy to lose sight of that, but it’s true, because true Christianity isn’t about believing in beliefs, it’s about believing in a person: Jesus Christ, the Son of God, in whom the fulness of the Triune God is revealed. Doctrines, even true doctrines, don’t save us—only Jesus saves us; it matters that we believe true things, yes, but we seek to believe true things in order that we may more clearly see and know and believe in the one who is Truth.
Christ cannot be summarized in propositional statements and assertions of fact; indeed, all the true statements we can make about him and his teaching are of necessity partial. We cannot follow him by making up a list of things to do and not to do, or by identifying the things he did and trying to do them; we cannot help others know him merely by telling them things about him, even if every last one of them are true things. Christian faith cannot ultimately be explained, nor can it fully be taught, even though teaching is an important element of the work of the church. In the end, it can only be lived, Christ in us by his indwelling Holy Spirit; and the only way we can fully carry out his command to make disciples is by living in him and allowing others to live closely with us as we do so, so that we can say to them, “Follow me as I follow Christ.”